Effects of short-term enclosure on the vegetation characteristics of a lightly degraded alpine meadow in Guinan County

Grassland degradation has seriously affected the development of animal husbandry on the Qinghai-Tibetan plateau. To clarify the influence of short-term enclosure on the vegetation characteristics of alpine meadows, the short-term enclosure of a lightly degraded alpine meadow was conducted. The vegetation coverage, vegetation height, functional groups (grass, sedge, and forb), and annual dynamic change characteristics of the biomass inside and outside the fence were studied, to provide a scientific basis for the management of alpine meadows. The results showed that short-term enclosure could significantly improve the coverage, height, and aboveground biomass of a lightly degraded alpine meadow. In addition, the response of different plants to grazing exclusion was different. Grasses and forbs grew rapidly from July to August, while sedges gradually increased after September. In 2012, the sedge biomass accounted for over 60% of the total biomass on the ground, the grass biomass accounted for approximately 30%, and the forbs biomass was below 10%. Moreover, the grass, sedge, and total biomass in 2012 were higher than those in 2011. The average aboveground biomass increased by 12.4%, 161.5%, and 52.8% in July, August, and September, respectively, and the forbs biomass decreased by 57.1%. In summary, short-term enclosure can be used for the restoration and management of lightly degraded alpine meadows in Guinan County.